Question

我尝试了以下代码，但它没有工作：

<html>
<body>
<p id="demo"></p>
<p id="demo2"></p>

<script>

var max=1000;
var text=new Array();
var i=0;

for (i; i<=max ; i++) {
    text[i]=i;
}
var newx0=new Array();
newx0.push(text);
var rand = newx0[Math.floor(Math.random() * newx0.length)];
var randomx0=newx0[Math.floor(Math.random()* newx0.length)];
document.getElementById("demo").innerHTML = rand;
document.getElementById("demo2").innerHTML = newx0;

proglem是rand有价值的打印0到1000，就像newx0有价值的

Answer 1

new0是一个数组，其中包含一个元素：您的另一个text数组。这意味着newx0.length始终为1。你为什么要做那个数组包装呢？为什么不拥有

var rand = text[Math.floor(Math.random() * text.length)];
           ^^^^                            ^^^^

代替？

Answer 2

/**
 * Returns a random integer between min (inclusive) and max (inclusive)
 * Using Math.round() will give you a non-uniform distribution!
 */
function getRandomInt(min, max) {
    return Math.floor(Math.random() * (max - min + 1)) + min;
}

var array = [wherever your array comes from];     //Set up your array to be sampled
var randIndex = getRandomInt(0, array.length());  //Randomly select an index within the array's range
var randSelectedObj = array[randIndex];           //Access the element in the array at the selected index

getRandomInt来自这里： Generating random whole numbers in JavaScript in a specific range?

如何从数组中选择一个随机项？

2 个答案: